Gold prospecting in Arizona - any suggestions apart from lynx lake?

My uncle is an avid gold panner in Scotland. He is coming to Phoenix and would like to pan for gold. I understand that there are trespassing laws and claims on many areas. I know that Lynx Lake in Prescott has a designated area. Are there any other areas that he would be able to pan for gold and not require permission? I understand that there is a triangle area between Prescott, Phoenix and I-17 but where should I send him? Thank you